As described in JP 2007-315309 A, there has been known a fuel injection control device that controls a fuel injection amount of an injector. A fuel injection amount of the injector is determined by a fuel pressure in a delivery pipe and a valve opening period of the injector. The fuel injection control device calculates the fuel pressure in the delivery pipe and calculates the valve opening period of the injector on the basis of the calculated fuel pressure. Further, the fuel injection control device performs a feedback control in such a way that the fuel pressure in the delivery pipe is made constant.
The fuel injection control device calculates the fuel pressure in the delivery pipe at a given period and calculates the fuel pressure at the given period irrespective of a fuel injection start timing. For this reason, an error is caused between the calculated fuel pressure and the fuel pressure at the fuel injection start timing. The fuel injection control device corrects the fuel injection amount on the basis of a history of the fuel pressure, but a valve opening period of the injector is likely to be made excessively long or short because of the error. For this reason, the fuel injection amount outputted from the injector is likely to be shifted from an aimed fuel injection amount.